Contact shim for electrical receptacles



Oct. 14, .1941. J. w. HUNT 2,259,201

CONTACT SHIM FQR ELECTRICAL RECEPTACLES Filed Aug. 7, 1940 Inventor Aiiomey Patented Oct. 14, 1941 CONTACT SHIlVI FOR. EIiECTRICALRECEPTACLES John Whitsel Hunt, Philadelphia, Pa.'

Appiication August 7, 1940, Serial No. 351,690

1 Claim.

My invention relates to means for improving the mechanical andelectrical efficiency of the spring contacts in electrical plugreceptacles which have been subjected to long service and have becomeWorn or relaxed, and the primary object of my invention is to providesimple and effective means of this character which are readily appliedto the receptacles Without cutting off the house current or otherelectrical system, and without danger to the person applying the same.

Other important objects and advantages of my invention will be apparentfrom a reading of the following description taken in connection with theappended drawing wherein for purposes of illustration I have shown apreferred embodiment of my invention.

In the drawing:

Figure l is a general vertical longitudinal sectional view taken througha generally conventional form of electrical receptacle showing means inaccordance with the present invention applied thereto.

Figure 2 is a perspective view of one of the spring shims.

Figure 3 is a perspective view taken at right angles to Figure 1 andshowing the insulated applicator connected to the shim.

Figure 4 is a perspective. view showing an advanced position of theapplicator with respect to one of the shims.

Figure 5 is a perspective view of the fiat bar material from which thespring shims are made. Electrical plug receptacles are in many casessubjected to much wear and tear because of the frequent and carelessconnection and disconnection of electrical plugs therewith, so thatafter a certain amount of service the contacts of these receptaclesrelax, become loose, or are worn to such an extent that the blades ofthe plug no longer make a good mechanical and electrical connection withthe spring contacts of the receptacle. In order to remedy this situationand restore a good mechanical and electrical connection between theblades of the plug and the spring contacts of the receptacle, at smallcost and little trouble, I have provided spring shims which can be soldin dime stores on cards together with an insulated applicator so thatanyone can readily restore the efiiciency of the receptacles in his homeor other place and thereby avoid the necessity of removal of thereceptacles for repair, involving cutting oil the current supply and theexpense of the repairs.

The shims designated by the numeral 5 in the drawing consist of a flatbar 6 of uniform width and length and preferably of spring brass whichis bent at its middle to provide the curved bight I and the similarlyangularly divergent arms or legs 8 and 9, respectively. The free ends ofthe said arms are curvedly laterally outwardly defiected to provide theabutments l0 and II. In the first operation of applying the shims 5 theabutments I0 and II are seated in the notch [2 having beveled ends l3 inthe relatively wide head I4 on the shank l5 of the applicator which isgenerally designated [6 and which is formed of some suitable insulatingmaterial. When the shim has been entered through the slot H in the front18 of the receptacle which is generally designated IS, the applicator I6 is moved sidewise so as to disengage the notch l2 from the abutments,and then the free end of the shank I5 is placed between the arms of theshim to engage the bight 1, and the shim is then pushed home in thereceptacle until the shim seats and clicks are heard indicating properapplication of the shim, when the applicator is withdrawn. It will benoted that during both stages of the application of the shim contact ofthe hands with the shim is prevented by the insulated materialapplicator, thereby avoiding shocks to the person applying the shims.

When the shims are in place in the receptacle in installed position theterminals of the abutments [0 and I I engage the inner face of the frontI8 of the receptacle above and below or at opposite sides of the bladeentrance [1, with the laterally outward side of the abutment I 0engaging the bent end 20 of the hairpin-shaped existing contact 2|, sothat the laterally outward side of the shim arm 8 lies along theadjacent arm of the receptacle contact, and a goodly portion of theremaining arm 9 of the shim lies along the partition member 22 of thereceptacle. The combined tensioning produced by the tendency of the shimarms 8 and 9 to expand away from each other and the tendency of the arm23 of the receptacle contact to expand in the opposite directionproduces a good electrical and mechanical engagement between thereceptacle contact and the shim so that when the blade of the connectorplug (not shown) is passed into the entrance opening I! the blade willengage the laterally inward sides of the shim arms 8 and 9 and bfrictionally, mechanically and electrically engaged on both sidesthereof. The aperture between th arms 8 and 9 of the shim in theinstalled position is such as to bring about original or better thanoriginal grip on the blade of the connector plug, so that accidental ortoo easy disconnection of the plug limit the application of theinvention to the pre- 7 cise structure and arrangement shown except asmay be required by the scope of the subjoined claim.

Having described the invention, as new is:

7 15 whatis claimed In combination, an electrical receptacle comprisinga front wall having a plug blade entrance and an internal springcontact, said spring contact having a spring arm positioned obliquelywith respect to said entrance and spaced from another wall of saidreceptacle, a shim between said spring arm and said wall, said shimconsisting of a pair of divergent spring arms having their free endsengaging said front wall on opposite sides of said entrance, with one ofsaid arms lying along and electrically engaging the outer surface ofsaid spring arm of the receptacle contact, said shim having itsremaining spring arm engaging said other wall of the receptacle, and ayoke connecting the ends of said spring arms of the shim remote fromsaid entrance.

JOHN WHITSEL HUNT.

